Arene metal carbonyls



United States Patent 3,378,569 ARENE METAL CARBONYLS Roy L. Pruett,Charleston, and John E. Wym'an, St. Albans, W. Va., and Donald R. Rinkand Leo Parts, Buffalo, N.Y., assignors to Union Carbide Corporation, acorporation of New York No Drawing. Filed Sept. 12, 1958, Ser. No.760,558 5 Claims. (Cl. 260-3403) This invention relates toorgano-metallic carbonyls. More particularly, this invention relates toarene metal carbonyl wherein the metal is chromium, molybdenum ortungsten.

Bis(arene)organo-metallic compounds in which two aromatic hydrocarbongroups are bonded to each metal atom, for example bis(benzene)chromiumand bis(benzene)molybdenum, have been described. Such compounds and amethod for their preparation are disclosed in several published articlesby E. O. Fischer and coworkers. See, for example, Z. Naturforshung, (b),665 (1955); Chem. and Ind, 1956, 153; Z Anorg. Allgem. Chem, 286, 142(1956); ibid., p. 146; Ber., 89, 1805 (1956); ibid., p. 1809; and Angew.Chem, 68, 462 (1956). The organic groups of the bis(arene)metalcompounds of the published articles include only hydrocarbon groups,such as benzene, mesitylene and tetrahydronaphthalene.

We have now discovered a new and useful class of organo-metalliccompounds wherein only one arene organic group is bonded to each metalatom and wherein the arene organic group may contain any of a widevariety of chemical elements and functional groups.

These novel organo-metallic compounds are arene metal carbonyls, forexample benzene chromium tricarbonyl.

We have further discovered a. process by which the organo-metalliccompounds of this invention may be produced.

The compounds of this invention may be represented by the formulaArM(CO) where M is selected from the group consisting of chromium,molybdenum and tungsten and Ar is an arene organic compound containingthe benzenoid ring system. The benzenoid ring system is the six-carbon,unsaturated ring which may be represented by the structural formula Thesimplest members of the class of compounds represented by the aboveformula are benzene chromium tricarbonyl, benzene molybdenum tricarbonyland benzeue tungsten tricarbonyl. Additional examples of compound ofthis invention which illustrate the above formula are the following:

Alltyl substituted compounds such as toluene chromium tricarbonyl,mesitylene chromium tricarbonyl, cumene chromium tricarbonyl, toluenemolybdenum tricarbonyl, toluene tungsten tricarbonyl,9,10-dihydroanthrocene chromium tricarbonyl, and hexamethyl benzenechromium tricarbonyl.

Aryl substituted compounds such as biphenyl chromium tricarbonyl,terphenyl chromium tricarbonyl, quaterphenyl chromium tricarbonyl,biphenyl molybdenum tricarbonyl, biphenyl tungsten tricarbonyl, andalphanaphthyl benzene chromium tricarbonyl.

Aralkyl substituted compounds such as diphenyl methane chromiumtricarbonyl, alpha-naphthyl phenyl methane chromium tricarbonyl,diphenyl ethane chromium tricarbonyl, diphenyl methane molybdenumtricarbonyl, and diphenyl methane tungsten tricarbonyl.

Alkoxy substituted compounds such as anisole chromium tricarbonyl,phenetole chromium tricarbonyl, 1,3- dimethoxybenzene chromiumtricarbonyl, anisole molybdenum tricarbonyl, and anisole tungstentricarbonyl.

Aryloxy substituted compounds such as diphenyl ether chromiumtricarbonyl, 1,3-diphenoxybenzene chromium tricarbonyl,1,4-diphenoxybenzene chromium tricarbonyl, diphenyl ether molybdenumtricarbonyl, and diphenyl ether tungsten tricarbonyl.

Alkenyl substituted compounds such as allylbenzene chromium tricarbonyl,styrene chromium tricarbonyl, alphamethylstyrene chromium tricarbonyl,allylbenzene molybdenum tricarbonyl and allylbenzene tungstentricarbonyl.

Alkhydroxy substituted compounds such as benzyl alcohol chromiumtricarbonyl, beta-phenyl ethyl alcohol chromium tricarbonyl,beta-B-tolylethyl alcohol chromium tricarbonyl, benzyl alcoholmolybdenum tricarbonyl, and benzyl alcohol tungsten tricarbonyl.

Hydroxyl substituted compounds such as phenol chromium tricarbonyl,resorcinol chromium tricarbonyl, phloroglucinol chromium tricarbonyl.,phenol molybdenum tricarbonyl, and phenol tungsten tricarbonyl.

Amino substituted compounds such as aniline chromium tricarbonyl,p-phenylene diamine chromium tricarbonyl, 1,3,5-triaminobenzene chromiumtricarbonyl, aniline molybdenum tricarbonyl, and aniline tungstentricarbonyl.

N-alkylamino substituted compounds such as N-methylaniline chromiumtricarbonyl, N-ethylaniline chromium tricarbonyl, N-n-butylanilinechromium tricarbonyl, N- methylaniline molybdenum tricarbonyl, andN-methylaniline tungsten tricarbonyl.

N,N-dialkylamino substituted compounds such as N,N- dimethylanilinechromium tricarbonyl, N,N-diethylaniline chromium tricarbonyl,N,N-di-n-butylaniline chromium tricarbonyl, N,N-dimethylanilinemolybdenum tricarbonyl, and N,N-dirnethylaniline tungsten tricarbonyl.

Halogeno substituted compounds such as chlorobenzene chromiumtricarbonyl, bromobenzene chromium tricarbonyl, iodobenzene chromiumtricarbonyl, fluorobenzene chromium tricarbonyl, chlorobenzenemolybdenum tricarbonyl, and chlorobenzene tungsten tricarbonyl.

Aldehydo substituted compounds such as benzaldehyde chromiumtricarbonyl, o-methylbenzaldehyde chromium tricarbonyl,p-methylbenzaldehyde chromium tricarbonyl, benzaldehyde molybdenumtricarbonyl, and benzaldehyde tungsten tricarbonyl.

Nitro substituted compounds such as nitrobenzene chromium tricarbonyl,m-dinitrobenzene chromium tricarbonyl, rn-nitrotoluene chromiumtricarbonyl, nitrobenzene molybdenum tricarbonyl, and nitrobenzenetungsten tricarbonyl.

Cyano substituted compounds such as benzonitrile chromium tricarbonyl,4-cyanobiphenyl chromium tricarbonyl, o-dicyanobenzene chromiumtricarbonyl, benzonitrile molybdenum tricarbonyl, and benzonitriletungsten tricarbonyl.

Acyl substituted compounds such as acetophenone chromium tricarbonyl,benzophenone chromium tricarbonyl, propiophenone chromium tricarbonyl,acetophenone molybdenum tricarbonyl, and acetophenone tungstentricarbonyl.

Sulfhydryl substituted compounds such as benzenethiol chromiumtricarbonyl, o-methyl sulfhydrylbenzene chromium tricarbonyl,p-methylsulfhydrylbenzene chromium tricarbonyl, benzenethiol molybdenumtricarbonyl, and benzenethiol tungsten tricarbonyl.

Alkylsulfonyl substituted compounds such as methylsulfonyl-benzenechromium tricarbonyl, ethylsulfonylbenzene chromium tricarbonyl,propylsulfonylbenzene chromium tricarbonyl, methylsulfonylbenzenemolybdenum tricarbonyl, and methylsulfonylbenzene tungsten tricarbonyl.

Arylsulfonyl substituted compounds such as benzenesulfonyl benzenechromium tricarbonyl, p-diphenylsulfonyl benzene chromium tricarbonyl,o-tolylsulfonylbenzene chromium tricarbonyl, benzene suifonyl benzenemolybdenum tricarbonyl, and benzenesulfonyl benzene tungstentricarbonyl.

Carboalkoxy substituted compounds such as carbomethoxybenzene chromiumtricarbonyl, carbcethoxybenzene chromium tricarbonyl, dibutylphthalatechromium tricarbonyl, carbomethoxybenzene molybdenum tri carbonyl, andcarbomethoxybenzene tungsten tricarbonyl.

Carboxamido substituted compounds such as benzamide chromiumtricarbonyl, N-methylbenzamide chromium tricarbonyl, o-toluamidechromium tricarbonyl, benzamide molybdenum tricarbonyl, and benzamidetungsten tricarbonyl.

Carboxyl substituted compounds such as benzoic acid chromiumtricarbonyl, phthalic acid chromium tricarbonyl, toluic acid chromiumtricarbonyl, benzoic acid molybdenum tricarbonyl, and benzoic acidtungsten tricarbonyl.

Sulfonamido substituted compounds such as benzenesulfonamide chromiumtricarbonyl, o-methylbenzenesulfonamide chromium tricarbonyl,p-methy1benzenesulfonamide chromium tricarbonyl, benzenesulfonamidemolybdenum tricarbonyl, and benzencsulfonamide tungstcn tricarbonyl.

Benzene rings substituted with mixed substituents such as alkyl, alkoxybenzene: for example, anethole, may also form the compounds of thisinvention. Still other examples are p-cresol chromium tricarbonyl,salicylaldehyde chromium tricarbonyl, anisaldehyde chromium tricarbonyl,m-nitroaniline chromium tricarbonyl, p-chlorophenol chromiumtricarbonyl, para-chlorotoluene chromium tricarbonyl,o-N,N-dimethylaminotoluene chromium tricarbonyl, andp-dimethylaminobenzaldchyde chromium tricarbonyl.

Therefore, the compounds of this invention may also be represented bythe formula (CO)a wherein M is selected from the group consisting ofchromium, molybdenum and tungsten and the R groups may be the same ormixed and may be hydrogen and other benzenoid ring system substituentssuch as alkyl, aryl, aralkyl, alkaryl, alkenyl, alkoxy, aryloxy,alkhydroxy, hydroxyl, amino, N-alkyl amino, N,N-dialkylamino, halogeno,aldehydo, acyl, carboalkoxy, carboxamido, and carboxyl.

The bonding between the metal atom and the arene organic group takesplace through six electrons of the benzenoid ring system of the areneorganic group. This type of bonding is discussed in more detail in anarticle by E. O. Fischer and H. P. Kogler, Angew. Chem. 68, 462 (1956).The substituents on the benzenoid ring system must therefore be of suchsize and number that the benzenoid ring may approach the metal atomsufiiciently closely to permit stable bond formation to take place. Forexample, tertiary-butylbenzene chromium tricarbonyl andhexamethylbenzene chromium tricarbonyl are stable compounds, but1,3,S-tritertiary-butylbenzene chromium tricarbonyl is too unstable topermit isolation because the three bulky tertiary butyl groups do notpermit the henzenoid ring system to approach the chromium atomsulficiently closely for stable bond formation to take place.

The organo-metallic compounds of the present invention may becharacterized as addition compounds in contrast to organo-metallicsubstitution compounds. In the latter, a hydrogen or other substituentin the organic nucleus is substituted or removed in the formation of theorganometallic compound. However, no hydrogen, alkyl or othersubstituent is removed from or replaced on the arene organic moiety inthe formation of the arene metal carbonyls of this invention.

The compounds of this invention should be distinguished from additioncompounds such as the hexapyridine chromium cation, Cr(NC I-I whereinbonding between the metal and the organic group results from aconventional covalent (two electron) bond between the metal atom and oneother atom in the organic group.

According to the process for producing the compounds of this invention,an arene organic compound and a metal carbonyl are reacted either insolution or in the vapor phase. This process may be represented by theequation or, representing the arene organic group in more detail, by theequation wherein Ar, M and R have the meanings defined hereinabove.

The embodiment of the process wherein the reaction takes place in thevapor phase may be conveniently carried out by passing vapors of metalcarbonyl and arene organic compound through a glass, ceramic or metaltube heated to an elevated temperature. It is preferable to use astoichiometric excess of the arene organic compound.

The temperatures may vary over wide limits from the vaporizationtemperatures of the reactants up to the decomposition temperature of theproduct. Temperatures in the range from about 200 C. to about 300 C.give good yields of product and relatively rapid rates of reaction.

The reactant vapors may be undiluted or may be carried through thereaction zone in a stream of inert gas, such as nitrogen or argon. Atotal pressure of about one atmosphere is most convenient but higher orlower pressures may be used.

In the embodiment of the process wherein the reaction takes place in theliquid phase, it is preferable to employ an excess of the aromaticreactant as a solvent for the metal carbonyl. However, the reactionbetween the aromatic compound and the metal carbonyl may be carried outin an inert hydrocarbon solvent, such as heptane, petroleum ether or .anaromatic compound which does not form an arene metal carbonyl under theparticular reaction conditions.

In the preferred form of the liquid phase reaction, a basic catalyst isadded to the reaction mixture. The basic catalysts of this invention arebasic, nitrogen-containing liquid organic compounds, preferablyalkyl-substituted pyridines or tertiary amines such asN,Ndimethylaniline, tributylamine, 2 methylpyridine, 2,6dimethylpyridine, 2,4,6-trimethylpyridine and triethyl amine. Whenaniline or a derivative thereof is a reactant, no additional catalyst isnecessary. The catalyst increases the rate of reaction and thus makes itpossible to carry out the reaction at a lower temperature than thatrequired in the absence of a catalyst. Trace amounts of catalyst areeffective, but larger amounts are preferred, as described hereinbelow.

The temperatures at which the liquid phase reaction may be carried outmay vary over a considerable range of from 0 C. to 300 C. Temperaturesup to about 100 C. are often satisfactory but in the interest ofincreasing the rate of reaction, higher temperatures are preferred.Temperatures in excess of the decomposition temperature of the productsin the reaction medium employed should be avoided. Generally, it ispreferred to employ temperatures in the range of 100 C. to 250 C.

The time necessary to carry out the reaction varies over wide limitsdepending on the temperature employed. The yields are not materiallyreduced by long time maintenance of reaction mixture under reactionconditions. Carbon monoxide gas is evolved during the course of thereaction, and it is generally preferred to maintain the reactants underthe desired reaction conditions until carbon monoxide evolutionessentially ceases.

The ratio of reactants is not critical and such ratios may he variedover wide limits. However, it is preferable to use the aromatic reagentsin considerable stoichiometric excess, although stoichiom-etric amountsmay be used. Further, for good yields, at least equal amounts of themetal carbonyl and catalyst should be used, although small quantities ofthe catalyst may also be used with success. The best yields are obtainedwhen a considerable excess of both the catalyst and aromatic reactantare used.

When a metal carbonyl is reacted with a mixture of arene reactants, anarene metal carbonyl will form preferentially with the arene compoundhaving the stronger electron donating group or weaker electronwithdrawing group, as a substituent. In Example 9 hereinbelow,molybdenum hexacarbonyl was heated with equal volumes ofN,N-dimethylaniline and toluene. Since the dimethylamino group is astronger electron donor than the methyl group, N,N-dimethylanilinemolybdenum tricarbonyl was produced rather than toluene molybdenumtricarbonyl. Similarly, from a reaction mixture containing chromiumhexacarbonyl, chlorobenzene and benzaldehyde, the compound producedwould be chlorobenzene chromium tricarbonyl, not benzaldehyde chromiumtricarbonyl, because the chloro group is a weaker electron withdrawinggroup than the aldehyde group.

The compounds of this invention and the process for producing them areillustrated by the following examples:

Example 1.p-Xylene chromium tricarbonyl One hundred milliliters of2,4,fi-trimethylpyridine, 100 ml. of p-xylene and 2.0- g. of chromiumhexacarbonyl were placed in a 500 ml. round bottom flask equipped with acondenser. The reaction mixture was heated at a reflux temperature of147 C. for a period of six hours. After cooling to room temperature, thesolution was filtered and evaporated to an oily residue by heating underpartial vacuum in an oil bath at 110 C. The oily residue was thencrystallized by chilling. The solid was then taken up in boilingn-heptane and 1.56 grams of yellow crystals of p-xylene chromiumtricarbonyl were isolated. This represents a yield of 71% of theoreticalamount based on chromium hexacarbonyl. The melting point of the product,p-xylene chromium tricarbonyl is 9798 C. and the infrared spectrum isconsistent with the assigned structure.

Following the same procedure, 50 milliliters of pxylene, 2 grams (0.009mole) of chromium hexacarbonyl and 1.87 grams (0.01 mole) oftri-n-butylamine were reacted to yield 0.8 gram of yellow crystals ofp-xylene chromium tricarbonyl. This represents a yield of 36% based onCr(C0) Example 2.--Tetrahydronaphthalene chromium tricarbonylTetrahydronaphthalene (150* ml.), 50 milliliters of 2,4,G-trimethylpyridine, and 3.0 grams of chromium hexacarbonyl were placedin a SOD-milliliter round bottom flask equipped with a reflux condenserand heated at 150 to 160 C. for four hours. The reaction was carried outunder an argon atmosphere. An additional 50 milliliters oftetrahydronaphthalene were added and the solution refluxed for eighthours. The solution was cooled to room temperature and evaporated todryness under a partial vacuum. The yellow residue was dissolved inboiling nheptane and chilled to crystallize the crude product. Theyellow crystals were collected and twice; recrystallized from n-heptaneaffording a 2.2 gram yield of yellow crystals of tetrahydronaphthalenechromium tricarbonyl, M.P. 11S-l16 C. This represents a 60% yield basedon Cr(CO) Example 3.Toluene chromium tricarbonyl A mixture ofmilliliters of toluene, 100 milliliters of Z-methylpyridine, and 2.0grams of chromium hexacarbonyl was placed in a SOO-ml. flask and thereaction was carried out by the process of Example 1. Yellow crystals oftoluene chromium tricarbonyl, M.P. 79-81 C., were obtained.

Example 4.-Mesitylene chromium tricarbonyl One hundred milliliters ofmesitylene, 100 ml. of 2- methylpyridine, and 2.0 grams of Cr(CO) werereacted by the process of Example 1, to yield 1.4 grams of mesitylenechromium tricarbonyl, M.P. 174175 C. This represents a yield of 60%based on Cr(C0) Example 5.-p-Chlorotoluene chromium tricarbonylFollowing the procedure of Example 1, 2.0 grams of chromiumhexacarbonyl, 100 milliliters of Z-methylpyridine, and 100 millilitersof p-chlorotoluene were reacted to yield 1.4 grams of yellow crystals ofp-chlorotoluene chromium tricarbonyl, M.P. 89-91 C. This represents ayield of 60% based on Cr(CO) Example 6.-Anisole chromium tricarbonylFollowing the procedure of Example 1, 100 milliliters of redistilledanisole, 100 milliliters of Z-methylpyridine, and 2.0 grams of chromiumhexacarbonyl were reacted to yield 1.52 grams of yellow crystals ofanisole chromium tricarbonyl M.P. 8486 C. This represents a yield of 70%based on Cr(C0) Example 7.-Bromobenzene chromium tricarbonyl Followingthe procedure of Example 1, 100 milliliters of 2-methylpyridine, 100milliliters of bromobenzene, and 2.0 grams of chromium hexacarbonyl werereacted to yield 0.16 gram of dark yellow crystals of bromobenzenechromium tricarbonyl, M.P. 117-120 C. This represents a yield of 6%based on Cr(CO) Following the procedure in Example 1, 50 milliliters ofN,N-dimethylaniline, 50 milliliters of toluene and 3 grams of molybdenumhexacarbonyl were reacted to yield pale yellow crystallineN,N-dimethylaniline molybdenum tricarbonyl which decomposes withoutmelting at C.

Found: C, 44.6%; H, 3.6%; M0, 32.8%; N, 4.5%. Calculated for C H N(CHMo(CO) C, 43.9%; H, 3.7%; Mo, 31.9%; N, 4.7%.

Example 10.--Mesitylene molybednum tricarbonyl Following the procedureof Example 1, 2 grams of molybdenum hexacarbonyl, 4.4 grams oftri-n-butylamine and 50 milliliters of mesitylene were reacted to yieldpale yellow crystalline mesitylene molybdenum tricarbonyl whichdecomposes without melting at C. Example 11.N,N-Dimethylaniline tungstentricarbonyl Following the procedure of Example l, 50 milliliters ofN,N-dimethylaniline, 50 ml. of toluene and 3 grams of tungstenhexacarbonyl were reacted to yield bright yellow crystallinedimethylaniline tungsten tricarbonyl which turns green at 160 C. andmelts at 180 C. with gas evolution.

Following the same procedure but without the use of toluene as asolvent, 50 milliliters of N,N-dimethylaniline and 3 grams of tungstenhexacarbonyl were reacted to yield 2.5 grams of dimethylaniline tungstentricarbonyl. This represents a yield of 76% based on W(CO) Example12.Aniline chromium tricarbonyl Following the procedure of Example 1, 50milliliters of aniline, 50 milliliters of toluene and 3 grams ofchromium hexacarbonyl were reacted to yield bright yellow crystals ofaniline chromium tricarbonyl which melts without decomposition at156-158 C.

Found: C, 47.3%; H, 3.2%; Cr, 23.6%; N, 5.9%. Calculated for C H NHCr(CO) C, 47.2%; H, 3.1%; Cr, 22.7%; N, 6.1%.

Preparation of the hydrochloride of (l) N,N-dimethylaniline tungstentricarbonyl and (2) aniline chromium tricarbonyl: Each of the abovecompounds was treated in the following manner: about 0.2 gram wasdissolved in toluene and gaseous hydrogen chloride was bubbled throughthe solutions. The bright yellow, crystalline hydrochloridesprecipitated. These hydrochlorides were hygroscopic and reverted to thetoluene-soluble free amine metal tricarbonyls on contact with a mixtureof toluene and water. The hydrochloride of N,N-dimethylaniline oraniline does not ordinarily revert to the free amine on contact withwater. This shows that the complexing of the benzenoid ring :by theM(CO) unit decreases the base strength of the free amine.

Example 13.--p-Xylene tungsten tricarbonyl Following the procedure ofExample 1, 75 milliliters of p-xylene, 2 grams of tungsten hexacarbonyland 3 grams of tri-n-butylamine were reacted to yield bright yellowcrystalline p-xylene tungsten tricarbonyl which melts with decompositionat 160162 C.

Found: C, 34.9%; H, 3.1%; W, 50%. Calculated for C H.,(CH W(CO) C,35.3%; H, 2.7%; W, 49%.

Example 14.-Mesitylene tungsten tricarbonyl Following the procedure ofExample 1, 50 milliliters of mesitylene, 2 grams of tungstenhexacarbonyl and 10 cc. of triethylamine were reacted to yield 0.2 gramof yellow crystals of mesitylene tungsten tricarbonyl which sublimes at150 C. at 1 atmosphere and decomposes above 186 C.

Example .N,N-Dimethylaniline chromium tricarbonyl Example16.-2-Aminobiphenyl chromium tricarbonyl Following the procedure inExample 1, 10 grams of Z-amino-biphenyl, 2 grams of chromiumhexacarbonyl and 3 milliliters of toluene were reacted to yield brightyellow crystals of Z-aminobiphenyl chromium tricarbonyl.

Example 17.Biphenyl chromium tricarbonyl Following the procedure inExample 1, 10 grams of biphenyl, 2 grams of chromium hexacarbonyl andmilliliters of tri-n-butylamine were reacted to yield dark yellowcrystals of biphenyl chromium tricarbonyl which melts at 8081 C.

8 Found: C, 59.7%; H, 3.5%; Cr, 18.3%. Calculated for (C H Cr(CO) C,62.0%; H, 3.5%; Cr, 17.9%.

Example l8.Aniline molybdenum tricarbonyl Following the procedure ofExample 1, 2 grams of molybdenum hexacarbonyl, 50 milliliters of anilineand 5 milliliters of toluene were reacted to yield yellow crystals ofaniline molybdenum tricarbonyl.

Example 19.Aniline tungsten tricarbonyl Following the procedure ofExample 1, 2 grams of tungsten hexacarbonyl and 50 milliliters ofaniline were reacted to yield yellow crystals of aniline tungsten whichmelt at 120121 C. with decomposition and which were identified byinfrared analysis.

Example 20.Cumene chromium tricarbonyl Following the procedure ofExample 1, 2 grams of chromium hexacarbonyl, 25 ml. of tri-n-butylamineand 100 milliliters of cumene were reacted to yield 1.5 grams of yellowcrystals of cumene chromium tricarbonyl. This represents a yield ofbased on Cr(CO) Example 2l.Toluene chromium tricarbonyl Vapors of Cr(CO)and toluene were passed through a Pyrex tube heated to a maximumtemperature of 340 C. Yellow crystals of toluene chromium tricarbonylbegan to collect at the downstream end of the reaction tube when thetemperature reached 220 C. The rate of reaction appeared to increase upto 250 C. where a chromium mirror began to form on the walls of thereaction tube. A total of 1.3 grams of Cr(CO) was vaporized and passedthrough the tube, yielding 0.8 gram of yellow toluene chromiumtricarbonyl. This represents a yield of 59% based on Cr(CO) Example22.Alpha-methyl styrene chromium tricarbonyl Fifty (50) milliliters ofalpha-methyl styrene inhibited with tertiary butyl catechol, 50milliliters of tri-n-butylamine and 2 grams of chromium hexacarbonylwere placed in a 200 milliliter boiling flask which had been purged withargon. The reaction was carried out under a protective atmosphere ofargon throughout. The reaction mixture was heated to boiling (170 C. andallowed to reflux 1 /2 hours until carbon monoxide evolution ceased. Thedark yellow solution was then stripped to dryness under a partialvacuum. A yellow crystalline solid was obtained which was recrystallizedfrom n-heptane to obtain 0.7 gram of yellof alpha-methyl styrenechromium tricarbonyl which has a melting point of 77-78 C. with noapparent decomposition. The structure and composition of this compoundwere confirmed by intrared and elemental analysis. A 30% yield based onchromium was obtained.

Example 23.-Durene chromium tricarbonyl Two hundred (200) milliliters ofZ-methylpyridine, 2.0 grams of chromium hexacarbonyl and 25 grams ofdurene were reacted by the process of Example 1, to yield 0.7 gram ofdurene chromuim tricarbonyl, melting point 97 98 C. This represents ayield of 39% based on chromium hexacarbonyl.

Example 24.Tertiary-butylbenzene chromium tricarbonyl One hundredmilliliters (100 ml.) of Z-methylpyridine, 100 milliliters oftertiary-butyl benzene, and 2.0 grams of chromium hexacarbonyl werereacted by the process of Example 1, to yield 1.53 grams oftertiary-butylbenzene chromium tricarbonyl, melting point 7879 C. Thisrepresents a yield of 63% based on chromium hexacarbonyl.

Example 25.4-Methyl-2-phenyl-1,3-dioxolane chromium tricarbonyl Fifty(50) milliliters of 4-methyl-2-phenyl-1,3-dioxolane, milliliters of2-rnethylpyridine, and 2.0

grams of chromium hexacarbonyl were reacted by the process of Example 1to give 4-methyl-2-phenyl-1,3-dioxolane chromium tricarbonyl as anintractable oil.

Example 26.-Benzaldehyde diethylacetal chromium tricarbonyl A mixture of3.0 grams of chromium hexacarbonyl, 50 milliliters of benzalde-hydediethylacetal, and50 milliliters of Z-methylpyridine were reacted by theprocess of Example 1 to give 2.1 grams of benzaldehyde diethylacetalchromium tricarbonyl, melting point l-52 C. This represents a yield of50% based on chromium hexacarbonyl.

Example 27.Benzaldehyde chromium tricarbonyl A mixture of 1.5 grams ofbenzaldehyde diethylace-tal chromium tricarbonyl and 35 milliliters ofWater containing 3 drops of concentrated hydrochloric acid was placed ina stoppered test tube under argon and allowed to react with occasionalshaking for a six-hour period. The resulting orange solid was filteredin a dry box using argon as the inert atmosphere. The solid material wasa mixture of benzaldehyde chromium tricarbonyl and benzaldehydediethylacetal chromium tricarbonyl. This mixture was then shakencontinuously for six hours with 30 milliliters of water containing 3drops of concentrated hydrochloric acid in a stoppered test tube underan argon atmosphere. The following operations were conducted in a drybox using argon as the inert atmosphere. The resulting red aqueoussolution containing some red oil was extracted with toluene until theaqueous layer was colorless. 'I he toluene layer was dried over sodiumsulfate, filtered and evaporated to dryness under a partial vacuum. Theresulting mixture of a red oil and red crystals was recrystallized from100 milliliters of boiling heptane, cooled in a Dry Ice bath, andfiltered aifording 1.0 gram of benzaldehyde chromium tricarbonyl. Thisrepresents a yield of 83%, based on benzaldehyde diethylacetal chromiumtricarbonyl.

Example 28.-N-methylaniline chromium tricarbonyl Following the procedureof Example 1, 100 milliliters of N-methylaniline and 3.0 grams ofchromium hexacarbonyl were reacted to yield 2.65 grams of yellowcrystals of N-methylaniline chromium tricarbonyl which melts withoutdecomposition at 120l2l C. This represents an 80% yield, based onchromium hexacarbonyl. The infrared spectrum was consistent with theassigned structure.

Example 29.Acetophenone diethylketal chromium tricarbonyl Following theprocedure of Example 1, 50 milliliters of 2-methylpyridine, 50milliliters of acetophenone diethylketal, and 3.0 grams of chromiumhexacarbonyl were reacted to give 2.13 grams of yellow platelets ofacetophenone diethylketal chromium tricarbonyl, melting point 4143 C.This represents a yield of 46% based on chromium hexacarbonyl.

Example 30.Ace-tophenone chromium tricarbonyl A stoppered test tubecontaining 1.5 grams of acetophenone diethylketal chromium tricarbonyl,35 milliliters of water, and 3 drops of concentrated hydrochloric acidwas mechanically shaken for six hours. The reddish orange solidremaining in the test tube was dissolved in toluene and the aqueouslayer extracted with toluene. The combined toluene extracts were driedover sodium sulfate, and evaporated to dryness in a partial vacuum at 40C. The red crystalline solid was recrystallized twice from heptanealfording 0.8 gram of golden yellow crystals of acetophenone chromiumtricarbonyl. This represents a yield of 64%, based on acetophenonediethylketal chromium tricarbonyl.

The sample of the material melted at 48-50 C. after shaking with 40 ml.of water containing 3 drops of concentrated hydrochloric acid, washing,and drying.

Example 31.-Benzyl alcohol chromium tricarbonyl A mixture of 50milliliters of benzyl alcohol, 50 milli liters of Z-rnethylpyridine and2.0 grams of chromium hexacarbonyl were reacted by the process ofExample 1 to give 0.8 gram of benzyl alcohol chromium tricarbonyl,melting point 96-98 C. This represents a yield of 63% based on chromiumhexacarbonyl.

Example 32.-Diphenylmethane chromium tricarbonyl A mixture of 50milliliters of diphenylmethane, 150 milliliters of Z-methylpyridine and2.0 grams of chromium hexacarbonyl were reacted by the process ofExample 1 to give 1.52 grams of diphenylmethane chromium tricarbonyl,melting point 99-1 01 C. This represents a yield of 56% based onchromium hexacarbonyl.

Example 33.-Benzoic acid chromium tricarbonyl Ethyl benzoate chromiumtricarbonyl, obtained from the reaction of 5.0 grams of chromiumhexacarbonyl, 100 milliliters of triethylamine, 100 milliliters ofZ-methylpyridine, and 100 milliliters of ethyl benzoate, was added to asolution of 5.0 grams of potassium hydroxide in 45 milliliters of waterand the mixture allowed to stand for 3 days at room temperature. Theyellow solution, which did not contain unreacted ethyl benzoate chromiumtricarbonyl, was filtered and acidified with concentrated hydrochloricacid after the addition of about 20 grams of ice. The resulting cloudyorange solution was then extracted with ether (three 50 milliliterportions), the ether extracts dried after washing with distilled water(three 50 milliliter portions), and evaporated to dryness in partialvacuum. The resulting orange-yellow solid was dissolved in the minimumamount of ether and evaporated to dryness in a stream of argon to givebenzoic acid chromium tricarbonyl. The compound was obtained as anorange-red solid, soluble in aqueous base, insoluble in heptane andwater, difiicultly soluble in benzene and very soluble in ether.

The compounds of this invention may be used to deposit a metallic mirroron various substrates. All of the compounds of this invention can bedecomposed by employment of temperatures in excess of 400 C. to form ametallic film or coating on materials such as glass, glass cloth, resinsand metals. The metallic coatings provide electrically conductingcoatings for such substances as glass cloth and provide corrosionresistant coatings for metals.

For coating glass cloth, a quantity of an arene metal tricarbonyl ofthis invention is sealed in an evacuated glass tube with a strip ofglass cloth which has previously been dried in an oven at C. for onehour; the tube is then heated to about 400 C. for one hour, cooled andopened. The glass cloth increases in weight by up to about 0.01 gram pergram of glass cloth and has a resistivity of approximately 2 ohms percentimeter. Thus, a conducting cloth may be prepared which is useful forthe reduction of static charge.

For example, a piece of thin copper wire about 43 millimeters long, apiece of sapphire rod 3 millimeters in diameter and 22 millimeters long,and a rectangular piece of glass cloth about 50 x 20 millimeters averagedimension were placed in a 30 millimeter OD. glass tube 2 feet long. Aglazed porcelain boat containing 1 gram of toluene chromium tricarbonylwas placed in the tube which was then purged with argon and heated to300 C. The boat was then pushed into the hot zone. After 45 minutes, achromium plate was deposited on the objects as well as on the walls ofthe tube, and toluene was condensing on the cool downstream end of thetube.

The glass cloth had attained a very dark metallic luster and wouldconduct an electric current. The copper Wire had a dull, even coating ofchromium rnetal over its entire length. The sapphire rod had an even,bright, shiny 1 1 surface coating of chromium metal and this chromiumplate had a resistance of 150 ohms from one end to the other.

The alkenyl substituted compounds of this invention may also be used toprepare light sensitive polymers. Such polymers are useful in preparingpaper suitable for photo reproduction.

For example, alpha-methyl styrene chromium tricarbonyl (.3 gram, 0.001mole), and .5 gram (0.005 mole) of styrene catalyzed with a few crystalsof 1,1-azo-bisl-cyclohexane nitrile were placed in an argon purgedreaction vessel. The reaction was carried out in an inert atmosphere ofargon throughout. The reaction mixture was heated to 110 C. for threehours at which time the reaction mixture Was nearly solid. Thestyrene-alphamethyl styrene chromium tricarbonyl co-polymer was taken upin toluene. The toluene, styrene-alpha-methyl styrene chromiumtricarbonyl co-polymer mixture was added to about 150 milliliters ofmethanol and the polymer filtered out. Analysis of the productcorresponds to one alpha-methyl styrene chromium tricarbonyl moleculeper 5.25 styrene molecules. The copolymer softens at about 140 C. andchanges from yellow to green on exposure to light.

What is claimed is:

1. Alpha-methyl styrene chromium tricarbonyl.

12 2. 4-methyl-2-phenyl 1,3 dioxolane chromium tricarbonyl.

3. Benzaldehyde diethylacetal chromium tricarbonyl. 4. Acetophenonediethylketal chromium tricarbonyl. 5. A styrene polymer chromiumtricarbonyl.

References Cited UNITED STATES PATENTS 12/1957 Brown et al. 260429 OTHERREFERENCES TOBIAS E. LEVOW, Primary Examiner.

ABRAHAM H. WINKELSTEIN, Examiner.

H. M. S. SNEED, W. J. VAN BALEN, L. C. BROWN,

B. D. WIESE, Assistant Examiners.

2. 4-METHYL-2-PHENYL - 1,3 - DIOXOLANE CHROMIUM TRICARBONYL. 